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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
"""
Outputter to generate C++ code for metrics.
"""
import jinja2
from glean_parser import metrics, util
from mozbuild.util import memoize
from util import generate_metric_ids, generate_ping_ids, get_metrics
def type_name(obj):
"""
Returns the C++ type to use for a given metric object.
"""
if getattr(obj, "labeled", False):
class_name = util.Camelize(obj.type[8:]) # strips "labeled_" off the front.
label_enum = "DynamicLabel"
if obj.labels and len(obj.labels):
label_enum = f"{util.Camelize(obj.name)}Label"
if class_name == "Counter":
return f"Labeled<impl::{class_name}Metric<impl::CounterType::eBaseOrLabeled>, {label_enum}>"
return f"Labeled<impl::{class_name}Metric, {label_enum}>"
generate_enums = getattr(obj, "_generate_enums", []) # Extra Keys? Reasons?
if len(generate_enums):
for name, _ in generate_enums:
if not len(getattr(obj, name)) and isinstance(obj, metrics.Event):
return util.Camelize(obj.type) + "Metric<NoExtraKeys>"
else:
# we always use the `extra` suffix,
# because we only expose the new event API
suffix = "Extra"
return f"{util.Camelize(obj.type)}Metric<{util.Camelize(obj.name) + suffix}>"
generate_structure = getattr(obj, "_generate_structure", []) # Object metric?
if len(generate_structure):
generic = util.Camelize(obj.name) + "Object"
tag = generic + "Tag"
return f"ObjectMetric<{generic}, struct {tag}>"
if obj.type == "counter":
return "CounterMetric<impl::CounterType::eBaseOrLabeled>"
return util.Camelize(obj.type) + "Metric"
def extra_type_name(typ: str) -> str:
"""
Returns the corresponding C++ type for event's extra key types.
"""
if typ == "boolean":
return "bool"
elif typ == "string":
return "nsCString"
elif typ == "quantity":
return "uint32_t"
else:
return "UNSUPPORTED"
def structure_type_name(typ: str) -> str:
"""
Returns the corresponding C++ type for objects' structure types.
"""
if typ == "boolean":
return "bool"
elif typ == "string":
return "nsCString"
elif typ == "number":
return "int64_t"
else:
return "UNSUPPORTED"
def jsonwriter_prefix(typ: str) -> str:
"""
Returns the JSONWriter function prefix for a given structure type.
"""
if typ == "boolean":
return "Bool"
elif typ == "string":
return "String"
elif typ == "number":
return "Int"
else:
return "UNSUPPORTED"
def has_structure(all_objs) -> bool:
"""
Returns true if there's a metric in objs that needs a generated structure.
"""
for _, objs in all_objs.items():
for metric in objs.values():
if hasattr(metric, "_generate_structure"):
return True
return False
@memoize
def get_metrics_template(get_metric_id):
return util.get_jinja2_template(
"cpp.jinja2",
filters=(
("snake_case", lambda value: value.replace(".", "_").replace("-", "_")),
("type_name", type_name),
("extra_type_name", extra_type_name),
("structure_type_name", structure_type_name),
("jsonwriter_prefix", jsonwriter_prefix),
("has_structure", has_structure),
("metric_id", get_metric_id),
),
)
def output_cpp(objs, output_fd, options={}):
"""
Given a tree of objects, output C++ code to the file-like object `output_fd`.
:param objs: A tree of objects (metrics and pings) as returned from
`parser.parse_objects`.
:param output_fd: Writeable file to write the output to.
:param options: options dictionary.
"""
# Monkeypatch util.get_jinja2_template to find templates nearby
def get_local_template(template_name, filters=()):
env = jinja2.Environment(
loader=jinja2.PackageLoader("cpp", "templates"),
trim_blocks=True,
lstrip_blocks=True,
)
env.filters["camelize"] = util.camelize
env.filters["Camelize"] = util.Camelize
for filter_name, filter_func in filters:
env.filters[filter_name] = filter_func
return env.get_template(template_name)
util.get_jinja2_template = get_local_template
if "pings" in objs:
template = util.get_jinja2_template(
"cpp_pings.jinja2",
filters=(("ping_id", generate_ping_ids(objs)),),
)
if objs.get("tags"):
del objs["tags"]
else:
template = get_metrics_template(
options["get_metric_id"]
if "get_metric_id" in options
else generate_metric_ids(objs, options)
)
objs = get_metrics(objs)
output_fd.write(template.render(all_objs=objs, options=options))
output_fd.write("\n")